Epoxypropane wastewater optimization treatment device and method

Abstract

According to the epoxypropane wastewater optimization treatment device and method, oil-containing, hydrogen peroxide-containing, hydrazine-containing nitrile hydrazone ether-containing impurities and alcohol-containing wastewater are stored in a classified manner and treated in a classified manner, and the epoxypropane wastewater optimization treatment device and method have the advantages that the process is short, pollution is treated with pollution, cooperative treatment is achieved, the dosage of chemicals is small, the resource recovery rate is high, and energy and land are saved; oil removal treatment is independently carried out on sewage, the oil removal effect is good, and the water amount is small; the digestion of hydrogen peroxide and the cracking of impurities such as hydrazine nitrile hydrazone ether are coupled for treatment, and the inhibition of hydrogen peroxide on microorganisms is optimized as a digestion agent for biological inhibition factors; all wastewater is subjected to anaerobic biological treatment, and methane gas carbon resources are recycled; the high-efficiency aerobic biological fluidized bed reactor is used for carrying out standard treatment, so that the requirement of carbon emission reduction is fully met; the treated low-concentration wastewater is refluxed in situ, and the wastewater in the anaerobic reactor is diluted, so that the efficiency is better.

Description

Technical Field

[0001] The invention relates to the technical field of industrial wastewater treatment, and in particular to a device and method for optimizing treatment of propylene oxide wastewater. Background Art

[0002] Propylene oxide (PO), together with polypropylene and acrylonitrile, is known as one of the three major propylene derivatives. It is an important basic organic chemical raw material and is widely used in the automotive, construction, food, tobacco, pharmaceutical and cosmetic industries. With the gradual promotion of green technology, the direct oxidation of hydrogen peroxide (HPPO) method has become a common production process for new PO plants due to its simple process flow, high product yield and no pollution. Propylene oxide is produced by catalyzing the epoxidation of propylene with hydrogen peroxide (hydrogen peroxide). It is a clean production process with unique competitive advantages in terms of economy, environment and future development.

[0003] However, after the HPPO process was gradually industrialized, the oily wastewater and alkali wastewater (both of which are collectively referred to as hydrogen peroxide wastewater) produced by the hydrogen peroxide device, the alcohol-containing wastewater, salt-containing wastewater, and deetherification wastewater produced by the propylene oxide device, due to the complex water quality of the wastewater discharged by the device, there is no experience to refer to for treatment methods. Among them, the oil content in hydrogen peroxide wastewater is too high, the hydrogen peroxide concentration can be as high as 20%, and the impurities such as hydrazine, nitrile, hydrazone, ether in the salt-containing and deetherification wastewater have a lethal effect on anaerobic sludge microorganisms, resulting in COD in the water being difficult to remove and biological inhibition factors in the sewage, which greatly restricts the demand for expanding the production of this process. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the above-mentioned technical problems and provide a propylene oxide wastewater optimization treatment device and method, so as to treat pollution with pollution and coordinate management to achieve optimization of the wastewater treatment process in the HPPO device and maximize resource recovery, and improve the green production of HPPO technology in specific projects from the aspect of pollution control.

[0005] The technical scheme of the present invention is: a propylene oxide wastewater optimization treatment device, comprising a first regulating homogenizing tank, a second regulating homogenizing tank, a third regulating homogenizing tank, an air flotation oil removal device, a mixed chemical oxidation reactor, an anaerobic reactor, an aerobic biological fluidized bed reactor, a reflow pool, a biogas system, a dosing device, and an alkali solution adding device; the third regulating homogenizing tank, the air flotation oil removal device, the mixed chemical oxidation reactor, the anaerobic reactor, the aerobic biological fluidized bed reactor, and the reflow pool are connected in sequence; the second regulating homogenizing tank is connected to the mixed chemical oxidation reactor, and the dosing device is connected to the pipeline between the second regulating homogenizing tank and the mixed chemical oxidation reactor; the alkali solution adding device is connected to the pipeline between the mixed chemical oxidation reactor and the anaerobic reactor; the first regulating homogenizing tank is connected to the anaerobic reactor, and the biogas system is connected to the anaerobic reactor.

[0006] Preferably, the first regulating homogenizing tank is provided with a heater.

[0007] Preferably, the dosing device adds concentrated sulfuric acid and ferrous sulfate agents.

[0008] A method for optimizing the treatment of propylene oxide wastewater, using the above-mentioned propylene oxide wastewater optimization treatment device, comprises the following steps:

[0009] (1) The alcohol-containing wastewater is sent to the first regulating homogenization tank, and then sent to the anaerobic reactor after heating;

[0010] (2) The salt-containing wastewater and the deetherification wastewater are sent to a second regulating homogenization tank for mixing, and then, after adding concentrated sulfuric acid and ferrous sulfate reagents, they are sent to a mixed chemical oxidation reactor;

[0011] (3) The oily wastewater and the alkaline wastewater are sent to the third regulating homogenization tank for mixing, and then sent to the mixed chemical oxidation reactor after the oil is removed by the flotation device;

[0012] (4) The output of the mixed chemical oxidation reactor is added with alkali solution and then sent to an anaerobic reactor. The methane gas produced by the reaction is recovered through a biogas system; the wastewater is sent to an aerobic biological fluidized bed reactor;

[0013] (5) The wastewater is deeply treated in the aerobic biological fluidized bed reactor and then sent to the reflow pool. Part of the wastewater is returned to dilute the concentration of the wastewater entering the anaerobic reactor, and part of the wastewater is discharged in compliance with the standards.

[0014] The first regulating homogenization tank is used to regulate the water volume and water quality of alcohol-containing wastewater. The wastewater is heated by setting a heater to stabilize the reaction temperature of the medium in the anaerobic reactor within a certain range. The second regulating homogenization tank is used to regulate the water volume and water quality of salt-containing wastewater and deetherification wastewater. This part of wastewater contains high concentrations of hydrazine, nitrile, hydrazone, ether and other impurities, which are lethal to anaerobic sludge microorganisms. The third regulating homogenization tank is used to regulate the water volume and water quality of oil-containing wastewater and alkaline wastewater. This part of wastewater contains more oil and high concentration of hydrogen peroxide. If it cannot be effectively digested, it will have a sterilizing effect on subsequent microorganisms. The flotation device is used to remove the dirty oil in the wastewater to prepare for the subsequent hydrogen peroxide chemical oxidation , biological treatment improves conditions; the mixed chemical oxidation reactor is used for chemical oxidation of hydrogen peroxide. Under the catalytic action of acid and ferrous sulfate, hydrogen peroxide and impurities such as hydrazine, nitrile, hydrazone, ether, etc. are oxidized, on the one hand, hydrogen peroxide is digested, and on the other hand, impurities such as hydrazine, nitrile, hydrazone, ether, etc. are degraded, and coordinated governance is achieved; the anaerobic reactor is used for anaerobic treatment of high-concentration wastewater and recovery of methane gas; the aerobic biological fluidized bed reactor is used to treat wastewater in depth to meet standards; the wastewater returned from the reflow pool is used to dilute the concentration of wastewater entering the anaerobic reactor. Since the organic matter concentration of HPPO wastewater is very high, it directly enters the reactor and affects the operation. It is diluted with treated low-concentration wastewater and refluxed in large proportion. The biogas system is used to recover and treat the generated methane gas; the dosing device provides concentrated sulfuric acid and ferrous sulfate to the mixed chemical oxidation reactor; the alkali solution addition device adds alkali to the anaerobic reactor to maintain the alkalinity of the system.

[0015] The beneficial effects of the present invention are as follows:

[0016] The invention classifies and stores wastewater containing oil, hydrogen peroxide, hydrazine nitrile hydrazone ether and other impurities, and alcohol, and treats them by quality, and has the advantages of short process, pollution control by pollution, coordinated treatment, small dosage of reagent, high resource recovery rate, energy saving and land saving, etc.; the wastewater containing oil is treated separately, with good oil removal effect and small water volume; the digestion of hydrogen peroxide and the cracking of impurities such as hydrazine nitrile hydrazone ether are coupled to treat, and the inhibition of hydrogen peroxide on microorganisms is optimized to be used as a digester for biological inhibition factors; all wastewater is treated by anaerobic biology to recover methane gas carbon resources; a high-efficiency aerobic biological fluidized bed reactor is used for standard treatment, which fully meets the demand of "carbon emission reduction"; the treated low-concentration wastewater is refluxed on the spot to dilute the wastewater of the anaerobic reactor, and the efficiency is better; the invention has simple process, modularization and device design, reduces energy consumption and operation cost, and improves the operation stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the device flow of the present invention;

[0018] In the figure: 1. first regulating homogenizing tank; 2. second regulating homogenizing tank; 3. third regulating homogenizing tank; 4. flotation device; 5. mixed chemical oxidation reactor; 6. anaerobic reactor; 7. aerobic biological fluidized bed reactor; 8. recirculation pool; 9. biogas system; 10. dosing device; 11. alkali solution adding device; 12. alcohol-containing wastewater; 13. salt-containing wastewater; 14. deetherification wastewater; 15. oil-containing wastewater; 16. alkali-containing wastewater; 17. heater. DETAILED DESCRIPTION

[0019] like Figure 1 As shown: the present invention includes a first regulating homogenizing tank 1, a second regulating homogenizing tank 2, a third regulating homogenizing tank 3, an air flotation device 4, a mixed chemical oxidation reactor 5, an anaerobic reactor 6, an aerobic biological fluidized bed reactor 7, a reflow pool 8, a biogas system 9, a dosing device 10, and an alkali solution adding device 11; the third regulating homogenizing tank 3, the air flotation device 4, the mixed chemical oxidation reactor 5, the anaerobic reactor 6, the aerobic biological fluidized bed reactor 7, and the reflow pool 8 are connected in sequence; the second regulating homogenizing tank 2 is connected to the mixed chemical oxidation reactor 5, and the dosing device 10 is connected to the pipeline between the second regulating homogenizing tank 2 and the mixed chemical oxidation reactor 5; the alkali solution adding device 11 is connected to the pipeline between the mixed chemical oxidation reactor 5 and the anaerobic reactor 6; the first regulating homogenizing tank 1 is connected to the anaerobic reactor 6, the biogas system 9 is connected to the anaerobic reactor 6, and the first regulating homogenizing tank 1 is provided with a heater 17.

[0020] The process method of the present invention is as follows:

[0021] (1) The alcohol-containing wastewater 12 is sent to the first regulating homogenization tank 1, and after being heated, is sent to the anaerobic reactor 6;

[0022] (2) The salt-containing wastewater 13 and the deetherification wastewater 14 are sent to the second regulating homogenization tank 2 for mixing, and then are added with concentrated sulfuric acid and ferrous sulfate reagents and sent to the mixed chemical oxidation reactor 5;

[0023] (3) The oily wastewater 15 and the alkaline wastewater 16 are sent to the third regulating homogenizing tank 3 for mixing, and then sent to the mixed chemical oxidation reactor 5 after the oil is removed by the flotation device 4;

[0024] (4) The output of the mixed chemical oxidation reactor 5 is added with alkali solution and then sent to the anaerobic reactor 6. The methane gas produced by the reaction is recovered through the biogas system 9; the wastewater is sent to the aerobic biological fluidized bed reactor 7;

[0025] (5) The wastewater is deeply treated in the aerobic biological fluidized bed reactor 7 and then sent to the reflow pool 8. Part of the wastewater is returned to dilute the concentration of the wastewater entering the anaerobic reactor, and part of the wastewater is discharged in compliance with the standards.

[0026] The first regulating homogenizing tank 1 is used to regulate the amount and quality of alcohol-containing wastewater and heat the wastewater to regulate the reaction temperature of the medium in the anaerobic reactor to be stable within a certain range; the second regulating homogenizing tank 2 is used to regulate the amount and quality of salt-containing wastewater and deetherification wastewater; the third regulating homogenizing tank 3 is used to regulate the amount and quality of oil-containing wastewater and alkali-containing wastewater; the flotation device 4 is used to remove dirty oil in the wastewater; the mixed chemical oxidation reactor 5 is used for chemical oxidation of hydrogen peroxide; the anaerobic reactor 6 is used for anaerobic treatment of high-concentration wastewater and recovery of methane gas; the aerobic biological fluidized bed reactor 7 performs deep standard treatment on the wastewater; the wastewater returned from the reflow pool 8 is used to dilute the concentration of the wastewater entering the anaerobic reactor 6; the biogas system 9 is used to recover and treat the generated methane gas; the dosing device 10 provides concentrated sulfuric acid and ferrous sulfate reagents to the mixed chemical oxidation reactor 5; the alkali solution adding device 11 adds alkali to the anaerobic reactor to maintain the alkalinity of the system.

[0027] The first regulating homogenizing tank 1 is used to regulate the amount and quality of alcohol-containing wastewater and heat the wastewater to regulate the reaction temperature of the medium in the anaerobic reactor to a certain range and ensure the stable operation of the anaerobic reactor. 3 / h, COD≤40000mg / l, total nitrogen≤100mg / l;

[0028] The second regulating homogenizing tank 2 is used to regulate the water volume and water quality of salt-containing wastewater and deetherification wastewater. This part of wastewater contains high concentrations of hydrazine, nitrile, hydrazone, ether and other impurities, which have a lethal effect on anaerobic sludge microorganisms. Water volume 7m 3 / h, COD≤28300mg / l, total nitrogen≤1165mg / l;

[0029] The third regulating homogenizing tank 3 is used to regulate the water volume and water quality of oily wastewater and alkaline wastewater. This part of wastewater contains more oil and high concentration of hydrogen peroxide. If it cannot be effectively digested, it will have a disinfecting effect on subsequent microorganisms. Water volume 7m 3 / h, COD ≤ 35000mg / l, total nitrogen ≤ 150mg / l, petroleum ≤ 200mg / l, hydrogen peroxide ≤ 20%;

[0030] The flotation device 4 is used to remove the dirty oil in the wastewater, which improves the conditions for the subsequent hydrogen peroxide chemical oxidation and biological treatment. After the oil is removed, the petroleum content is ≤25mg / l;

[0031] Mixed chemical oxidation reactor 5 is used for chemical oxidation of hydrogen peroxide. Under the catalytic action of acid and ferrous sulfate, hydrogen peroxide and impurities such as hydrazine, nitrile, hydrazone, ether, etc. are oxidized to decompose hydrogen peroxide on the one hand and degrade impurities such as hydrazine, nitrile, hydrazone, ether, etc. on the other hand. Designed water volume 29m 3 / h;

[0032] Anaerobic reactor 6 is used for anaerobic treatment of high-concentration wastewater and recovery of methane gas. Since most of HPPO wastewater is high-concentration organic wastewater, anaerobic reactor is a crucial link. Design water volume 29m 3 / h, hydraulic retention time 24 hours, reflux ratio 200% ~ 500%, effluent COD ≤ 1000mg / l;

[0033] Aerobic biological fluidized bed reactor 7 treats wastewater to meet the requirements. Designed water volume 29m 3 / h, hydraulic retention time 12 hours, effluent COD ≤ 50mg / l;

[0034] The wastewater returned in the return water tank 8 is used to dilute the concentration of the wastewater entering the anaerobic reactor. Since the organic matter concentration of HPPO wastewater is very high, directly entering the reactor will affect the operation. It is diluted with treated low-concentration wastewater and returned in large proportion.

[0035] The biogas system 9 is used to recover and process the generated methane gas;

[0036] A dosing device 10 provides concentrated sulfuric acid and ferrous sulfate reagents to the mixed chemical oxidation reactor;

[0037] The alkali solution adding device 11 is used to add alkali to the anaerobic reactor to maintain the alkalinity of the system.

[0038] The above is only a typical example of the present invention and does not impose any formal limitation on the present invention. Any technical personnel familiar with the profession, without departing from the scope of the technical solution of the present invention, using the above technical content to make changes or modifications should be regarded as equivalent examples of equivalent changes. Any equivalent changes made to the above examples based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are within the scope of the technical solution of the present invention. Other undescribed parts of the present invention are the same as the prior art. It should be pointed out that for ordinary technical personnel in this technical field, without departing from the principles described in the present invention, several improvements or substitutions can be made, and these improvements or substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A propylene oxide wastewater optimization treatment device, characterized in that: It includes a first regulating homogenizing tank, a second regulating homogenizing tank, a third regulating homogenizing tank, an air flotation oil removal device, a mixed chemical oxidation reactor, an anaerobic reactor, an aerobic biological fluidized bed reactor, a reflow water tank, a biogas system, a dosing device, and an alkali solution adding device; the third regulating homogenizing tank, the air flotation oil removal device, the mixed chemical oxidation reactor, the anaerobic reactor, the aerobic biological fluidized bed reactor, and the reflow water tank are connected in sequence; the second regulating homogenizing tank is connected to the mixed chemical oxidation reactor, and the dosing device is connected to the pipeline between the second regulating homogenizing tank and the mixed chemical oxidation reactor; the alkali solution adding device is connected to the pipeline between the mixed chemical oxidation reactor and the anaerobic reactor; the first regulating homogenizing tank is connected to the anaerobic reactor, and the biogas system is connected to the anaerobic reactor.

2. The propylene oxide wastewater optimization treatment device according to claim 1, characterized in that: The first regulating homogenizing tank is provided with a heater.

3. A method for optimizing the treatment of propylene oxide wastewater, using the propylene oxide wastewater optimization treatment device as claimed in claim 2, characterized in that The following steps are involved: (1) The alcohol-containing wastewater is sent to the first regulating homogenization tank, and then sent to the anaerobic reactor after heating; (2) The salt-containing wastewater and the deetherification wastewater are sent to a second regulating homogenization tank for mixing, and then, after adding concentrated sulfuric acid and ferrous sulfate reagents, they are sent to a mixed chemical oxidation reactor; (3) The oily wastewater and the alkaline wastewater are sent to a third regulating homogenization tank for mixing, and then sent to a mixed chemical oxidation reactor after the oil is removed by an air flotation device; (4) The output of the mixed chemical oxidation reactor is added with alkali solution and then sent to an anaerobic reactor. The methane gas produced by the reaction is recovered through a biogas system; the wastewater is sent to an aerobic biological fluidized bed reactor; (5) The wastewater is deeply treated in the aerobic biological fluidized bed reactor and then sent to the reflow pool. Part of the wastewater is returned to dilute the concentration of the wastewater entering the anaerobic reactor, and part of the wastewater is discharged in compliance with the standards.

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